This invention relates to a numerical control system for numerically controlling machine tools.
Currently, a numerical control system is used for machine tools and thereby workpieces can be machined easily with high accuracy into any complicated shape.
A conventional numerical control system provides a control unit and workpiece can be machined in the following steps: data is read through an input unit from an input medium such as punched paper tape under the control of control unit, the data read causes the control unit and operation unit to process in accordance with memory contents stored in a memory unit, a machining data is supplied to a control object machine through an output unit based on the processing result, and such control object machine is controlled in accordance with machining data.
However, in the above conventional numerical control system, a specification program stored in the memory unit is previously fixed. Moreover, an expression indicating respective functions is used in programs to be input. For example, G01 is assigned to linear interpolation and the following expression is used, G01X1000Y-500F200. G01 means linear interpolation and the value following X means movement of work in the X axis direction, while value following Y means movement of a workpiece in the Y axis direction and value following F means a machining speed. In this case, a numerical control system reads the data, G01X1000Y-500F200 and judges the linear interpolation required and drives the means for driving the table in the directions of X axis and Y axis for the rate of 2:1 in the speed of vector direction of 200. The location of the table after movement by such driving is detected by a table location sensor whose output is fed to a numerical control system, and when a numerical control system has detected from an output of the table location sensor that the table has moved for 1000 in the direction of X axis and for -500 in the direction Y axis, the table driving means stops operation, the next program is executed and the machining is carried out in accordance with such program.
However, such conventional numerical control system has the disadvantage that a program becomes redundant because a program written by the codes preset in accordance with the functions of the numerical control system must be given, and the numerical control system cannot operate with a program written in a language not related to the code preset in accordance with said functions.